ÜDifference
between CHAIN and SETLL

·The CHAIN operation applies a record lock to files that are open or
update. The SETLL operation does not apply the lock.

·The CHAIN operation copies the record's data to the input buffer for
the program. The SETLL operation does not.

·If we just want to check for the existence of the record, then
SETLL is better option as CHAIN will put an extra overhead in copying the
data to input buffer.

·In CHAIN random access
operation is performed, while in SETLL READ EQUAL OR LESS operation is
performed.

·Resulting indicator in case of
CHAIN will be HI, while in case of
SETLL the operation will be EQ.

·CHAIN operation returns the returns only
if there is an exact match for the
key/RRN specified in factor-1, but in case of SETLL even there is not exact match the greater key value matching record will be positioned.